Excited state properties of IrIII(phpy)2(naphthylalaninate) with phpyH = 2-phenylpyridine: Energy transfer and luminescence

The complex IrIII(phpy)2(nala) with phpyH = 2-phenylpyridine and nalaH = 3-(2-naphthyl)alanine was prepared and characterized. The electronic spectrum of the complex shows long-wavelength absorptions which are attributed to the IrIII(phpy)2 chromophore. The lowest-energy excited state is a metal-to-ligand charge transfer (MLCT) triplet which is emissive under ambient conditions. Excitation of the naphthyl chromophore at shorter wavelength is followed by an efficient energy transfer to the IrIII(phpy)2 fragment.